11 Gantt Chart Questions Answered
Find the answers to all your burning questions about Gantt charts right here. And/or learn what a Gantt chart is in the first place.
Have you heard of something called a “Gantt chart,” but you’re not exactly sure what it is or how it can help you? You’re not alone. To be honest, most people have little more than a vague understanding of the wonders of the Gantt chart—unless they’re lucky enough to be deeply immersed in project management processes and terminology.
For the rest of us, who are just trying to manage our work better without having to catalogue the proper names of every chart and graph we use, there is still great value in getting acquainted with project management basics. And one of those basic building blocks is the Gantt chart.
There are reasons this chart has remained a staple of project management for over a hundred years now. It first achieved widespread use in WWI munitions factories. It went on to revolutionize manufacturing and major infrastructure projects. And it has even been a major player in the digital revolution we’re still experiencing today.
Get ready for a fascinating ride through the origins and current applications of this ubiquitous chart—the one chart that you should know by name. The Gantt chart.
1. What is a Gantt Chart?
In a nutshell, a Gantt chart takes a multi-step process that you’d otherwise have to document in outline or spreadsheet form, and it makes it visual. Digestible. Easier to comprehend and understand.
A Gantt chart represents your overall tasks and schedule as a cascading horizontal bar chart. It’s easy to see at a glance important details like:
- when tasks are supposed to begin and end
- how long each task should take
- to whom each task is assigned
- which tasks are occurring simultaneously
- which tasks are dependent upon predecessors
Rather than having to read and absorb countless overlapping details in a list format or a cell-by-cell spreadsheet, you can wrap your mind around the entire process more easily with a Gantt display.
2. How are Gantt Charts Used in Project Management?
Gantt charts are great at showing planned and actual progress of any number of tasks against a horizontal time scale. The tasks are arranged chronologically in a vertical list—often grouped into sub-projects—on the left side of the chart. The relevant dates stretch horizontally across the top of the chart, often grouped into weeks.
Gantt charts are especially helpful during the planning and execution phase of a project, and they are also useful in the event that resources must be reallocated. Today’s interactive Gantt charts make the process even easier, allowing you to drill down into any tasks or zoom out to full project or portfolio views.
3. What are the Advantages of Gantt Charts?
Speaking specifically of cloud-based interactive Gantt charts, like those available in the Workfront solution, the advantages are many. They allow you to:
- Plan out project tasks, subtasks and predecessors
- Allocate resources based on availability
- Assign necessary time frames
- Monitor progress and milestones in real time
- Dig deep into each task’s business value and resource requirements
- Zoom out to the portfolio level to see how different projects stack up
- Grant access to all project contributors and stakeholders
Even with these advantages, Gantt charts are best viewed as one of many project management tools to be used alongside other tools, so the strengths of each can be leveraged. Comprehensive work management solutions will gather each of these tools into one interactive space, allowing all of them to work seamlessly together.
4. What are the Disadvantages of Gantt Charts?
Gantt charts are often most easily used and understood by project management professionals. At first, they can seem incomprehensible to the uninitiated. If your team has a project manager or coordinator on staff who has the job of keeping projects on track, and that person understands how to wield the power of the Gantt chart, it can be a great solution, as part of a complete suite of project management tools.
But if you have a half-dozen “accidental project managers” on your team, all trying to access, update and understand the process individually, a Gantt chart may not be the most intuitive or complete option—especially if it serves as the lone documentation of your process.
Gantt charts also tend to work best with smaller, less complex projects. Why? The main focus of the Gantt chart is time. You have a vertical list of tasks, and you have a horizontal timeline. In a standard, standalone Gantt chart (meaning one that’s not plugged into a comprehensive work management solution), the full complexity and scope of the project are easily lost in translation, as are other details like cost and resource allocation.
5. Who was this Henry Gantt and How Did He Get a Chart Named After Him?
Henry Laurence Gantt was a mechanical engineer, management consultant, and all-around chart-making guy.
According to Wikipedia:
“He designed his charts so that foremen or other supervisors could quickly know whether production was on schedule, ahead of schedule, or behind schedule.”
Contrary to popular assumption, Gantt was not the inventor of the simple bar chart, which predated him by 100 years. His genius came through his focus on using effective measurement and planning to increase production. Gantt understood that there’s nothing inherently magical about any individual measurement tool; what matters is how you understand and leverage the insights it provides. In Gantt’s own words, as quoted in PM World Journal:
“The man who undertakes to introduce scientific management and pins his faith to rules, and the use of forms and blanks, without thoroughly comprehending the principles upon which it is based, will fail. Forms and blanks are simply the means to an end. If the end is not kept clearly in mind, the use of these forms and blanks is apt to be detrimental rather than beneficial.”
Gantt’s ideas are commonplace now, but they were revolutionary in their time. He wrote two books, Work, Wages and Profits in 1916 and Organizing for Work in 1919. His famous chart got its official name in later book by Wallace Clark, The Gantt Chart: a Working Tool of Management, published in 1923. All three books are in the public domain, and the full text can be read online using the links above.
The Gantt chart was used in WWI production and mercantile shipping efforts (at the instigation of General William Crozier) as well as the creation of the Hoover Dam and the Interstate Highway system.
In fact, when Colonel John T. Thompson, inventor of the Thompson submachine gun, received the Distinguished Service Medal at the end of World War I, he promptly sent a copy to Gantt with the following note:
“A large share in this reward for the accomplishment of a great war task is due to H.L. Gantt and his assistants. The Gantt general control production chart was my compass.”
If those aren’t good enough reasons to name a chart after someone, I don’t know what are.
6. Why Doesn’t Anyone Else Get to Have a Chart Named After Them?
It’s a good question. Most other charts used in project management have far more utilitarian names:
- PERT chart (Program Evaluation Review Technique), which grew out of the Gantt approach
- WBS chart (Work Breakdown Structure)
- Process Control Chart
- Stakeholder Analysis Matrix
- Cause and Effect Charts
- RACI (Responsibility Assignment Matrix)
Gantt himself always titled his charts according to their purpose, much like the list above. In fact, the Gantt chart would probably have a different name today, if Wallace Clark’s book hadn’t come along and placed it in elite company with just a few other charts that have managed to retain their creators’ immortal names:
- the Pareto chart, named after Vilfredo Pareto
- the Ishikawa diagram, named after Kaoru Ishikawa
- the Venn diagram, named after John Venn
7. How Can I Get a Chart Named After Me?
Unfortunately, there isn’t a chart registry service, as there is with stars. But if you develop a chart that revolutionizes the way work is done on a national or global scale, and someone writes a book about it, you may still stand a chance.
8. What Does a Modern Gantt Chart Look Like?
Here are two examples of Workfront’s dynamic Gantt charts.
The first shows a standard view of an individual project at the task level, with resources and deadlines visible over a narrow range of dates. The yellow line shows the current date. In the actual tool, it’s simple to scroll left and right to view earlier or later dates:
Here is the project and portfolio level view, which shows multiple projects across a greater time span:
9. Are Gantt Charts for Waterfall Project Management Only?
Gantt charts were developed back when there was really only one way to manage projects, so the methodology everyone followed didn’t have a name. It was just project management.
Now that alternative approaches have arisen, this traditional project management method is often called “Waterfall,” referring to the way that each stage in the project flows into the next, in a strictly linear fashion, as shown above. Gantt charts, which were developed under this paradigm, even visually look like a waterfall, at the task-level view at least, especially when the bars are colored blue. But that doesn’t mean they can’t have applications outside of the Waterfall world.
It wasn’t until the digital revolution that the inadequacies of Waterfall were revealed. Waterfall is great for building concrete projects like bridges and dams—and I mean “concrete” in both a literal and figurative way here—where there can be a clear vision and detailed plan outlined from the beginning. It’s not so great for fluid, ambiguous, completely unprecedented projects that are the norm in software development. The methodology that arose to manage these kinds of initiatives is called Agile project management.
Gantt charts are certainly most at home in Waterfall teams, but they can also be leveraged for teams that follow a mixed-methodology approach, departments where some teams are Waterfall and others are Agile, and even fully Agile teams.
Keep in mind that Waterfall is a mindset and overarching process, while Gantt scheduling is more of a tool or technique that can be adapted and applied in different situations.
10. Why Would an Agile Team Ever Use a Gantt Chart?
To be honest, hard-core Agile enthusiasts probably wouldn’t. Agile is a philosophy and a movement that even has its own manifesto. These kinds of conditions can tend to create rigid thinking around Agile, which is ironic, and some incorrectly assume that Agile is an all or nothing proposition.
But many teams successfully blend some aspects of Agile with some aspects of Waterfall, following a hybrid approach that suits their specific needs. For these mixed-methodology teams, and even for less-rigid Agile teams, there are certain situations where Gantt charts can be helpful in establishing more predictable project parameters. This is especially true for Agile or mixed teams that report in to Waterfall stakeholders.
Here’s how one project manager leverages Gantt charts in an Agile environment:
“Even if a project lends itself to naturally assume more Agile-based techniques, not having milestone dates worries most of my stakeholders. In response to this, I began to create a modified version of an Agile sprint backlog using Gantt charts.
This Gantt-backlog chart is a direct way of expressing responsibilities, milestones and the expected product. When updated everyday following a scrum, it shows the viewer progress in an intuitive way.
Clients know when to expect components of the project to be completed and they know when they can be expected to conduct their testing. There is a clear roadmap of how we would reach the final product.”
If that made no sense to you, don’t fret. Agile can sound like a foreign language at first, but it has proven to be worth the learning curve for software developers, marketers, and really any professionals who manage their work in unpredictable or ambiguous environments. And if you ever make the transition to an Agile approach, just know this: you can bring your Gantt charts with you.
11. Do I have to pronounce both of the T’s in Gantt?
Nott to the bestt of our knowledge.
One Hundred Years Young
There you have it: everything you never knew you wanted to know about Gantt charts, gathered together into one handy reference guide.
It’s remarkable, isn’t it? This one little chart, developed more than 100 years ago—even before the invention of sliced bread—is still finding applications in the most forward-thinking approaches to project management in our highly digitized world. That’s a testament to its utility, versatility, and endurance. Here’s to another hundred years of Gantt-influenced project planning.
Enjoy these additional posts that will introduce you to other project management basics: